Russia's Federal Security Service said it detained a Japanese journalist accused of gathering information on Russia's defence capabilities, news agencies reported on Tuesday.
FSB said the journalist for the Hokkaido Shimbun newspaper had been detained in the far eastern Sakhalin region before he planned to leave Russia, and was subsequently transferred to custody in Moscow, Interfax reported.
Russian state TV showed a man lying on a floor and handcuffed by three masked men in a black uniform. A voice behind the scene tells him he is suspected of spying.
TV also showed him boarding a plane accompanied by two FSB servicemen, then in a cage on trial in a Moscow court, which authorised his custody for nearly two months.
Russia regards Japan as an "unfriendly" country as it has joined Western sanctions against Moscow over the war in Ukraine.
Japan's embassy in Moscow did not answer phone calls out of business hours.
Russia and Japan never signed a formal World War Two peace treaty, with the main obstacle being an unresolved territorial dispute over the Kuril Islands, known in Japan as the Northern Territories.
Russian President Vladimir Putin visited one of the disputed islands in August, causing an uproar in Japan. Tokyo has said it would continue implementing sanctions against Russia and supporting Ukraine.
One of the most prominent cases of a foreign journalist arrested in Russia was the detention of Wall Street Journal reporter Evan Gershkovich in 2023.
He was found guilty of espionage by a Russian court, sentenced to 16 years and then freed in an East-West prisoner swap in August 2024.
